Azo dyestuffs and process for their manufacture



United States Patent 2,987,513 AZODYESTUEFS AND PROCESS FOR THEIR MANUFACTURE Karl-Heinz Schmidt, Koln-Flittard, Karl-Heinz Schiindehiitte and Fritz Suckfiill, Leverkusen, and Horst Nickel, KQ n-S am he mt Germ ny, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Dec. 9, 1958, Ser. No. 779,055

priority, application Germany Jan. 31, 1958 Th BIQ E I PYQ Qn relates to new azo dyestuiis and to a process {or their manufacture; more particularly it rel e t azo dye t ifis f h o mu N=N-R ion and to the copper complex compounds of said azo dyestuffs.

In the formula X means an azo (?N=N?) with azo components in the o-position to a group capable of forming metal complexes, by metallising the dyestufls, if desired, and by converting in the az o dyestuffs or their metal complex compounds thus obtained the nitro-group in the 6-position into a bridge member of the above said structure, containing at least two nitrogen atoms. The metal-free dyestuifs obtainable according to the new process may subsequently be metallised in substance oron the fibre. The metallisation may also be carried out in any other stage of the process.

The process according to the invention leads first to azo dyestufls of the following general formula In this formula R represents the radical of the said coupling component in which Z is. linked in he .O-PO- ice sition to the azo bridge, and Z denotes a substituent capable of forming metal complexes, preferably a hydroxyl group. The radical R may contain further substituents usual in azo chemistry. Dyestuifs containing a second azo group in the radical R are obtainable by coupling the diazo oxide with an azo component R containing a diazotizable amino group, said coupling occurring in 0- position to the Z substituent and by further diazotising and coupling this compound with an additional azo component, preferably in o-position to a metal complex forming group. By this method further azov groups and metal complex forming groupings can be introduced into the dyestuif molecule. These compounds are also 0btai nable by coupling the diazo oxide with an azo group containing coupling component R in o-position to Z.

The diazoxide to be used is obtainable by a method known as such in a simple manner by reacting the 6- nitro 1,2-naphthoquinone-4-sulfonic acid, with arylsulfonic acid hydrazide and by subsequently splitting the hydrazone in an aqueous alkaline medium. In many cases it is not necessary to isolate the diazoxide prior to the following coupling with the azo components. It has, on the contrary, been found that also the reaction mixture from the reaction of quinone with arylsulfonic acid hydrazide which still contains unsplit hydrazone can be used for the coupling reaction with the same result.

Suitable hydroxy compounds coupling in the o-position to a group capable of forming metal complexes are for example hydroxynaphthalenes such as l-hydroxynaphthalene-4-sulfonic acid, 2-hydroxynaphthalene-3,6-disulfonic acid, 8-ethoxy-1-hydroxynaphthalene-3,6-disulfonic acid, 2-acetylamino-5-hydroxynaphthalene-7-sulfonic acid, hydroxybenzenes, pyrazolones such as 1-(4'-sulfophenyl)- 3-methyl-pyraz0lone-(5), barbituric acid and the like, acetoacetic acid arylides, heterocyclic coupling components having substituents capable of forming metal complexes in the o position, azo compounds capable of coupling such as the azo dyestuff fiom diazotized 2- chloro-1-aminobenzene-5-sulfonic acid and 1,3-dihydroxybenzene.

The reactions for converting the nitro group customary in azo chemistry which are used in this case are the reductive linkage of two nitro group-containing molecules with the formation of an azo or azoxy grouping, the reduction of the nitro group to form an amino group with subsequent diazotising and coupling with azo components, or the reaction of the amino group obtained by reduction with polyfunctional acylating agents in the presence of a second amino component.

For the reaction of the nitroazo compounds which may be present in the form of their metal complex compounds, with reducing agents with a view to linking two molecules via an azo or azoxy grouping there may be used similar or also different nitroazo dyestulfs obtainable according to the invention. The reductive linkage is carried out for example by heating the components in the presence of reducing sugars in an aqueous medium, and it can also be efiected with the use of a nitroazo compound obtainable according to the present process and any other aromatic nitro compound.

By reduction of the nitro group in the 6-position in the azo compounds with, for example, sodium sulfide, with subsequent diazotization of the amino compound thus obtained and coupling with azo components, it is possible to build up dyestuffs of the most varied composition. In the case of a reduction of the nitro group with sodium sulfide, the metal complex formation is advantageously carried out at a later stage of the process, since the metal complexes are de-metallised by sodium sulfide.

When coupling the aminoazo compounds obtained by reduction of the nitro group, after diazotizing, with azo dyestufi molecule.

A r 2,987,513 '0 s .l SOaH (II) are thus obtained for the manufacture of which the following o-alkoXy-arnino compounds of the benzene and naphthalene series (R are for example suitable: 1- amino-Z-methoxy-benzeue, l-amino-Z-methoxy-S-methylbenzene, l-amino-2,5 dimethoxybenzene, 1 amino 2- methoxynaphthalene-6-sulfonic acid, l-amino-Z-ethoxynaphthalene-6-sulfonic acid. 'As coupling components (R there may be used: 1-hydroxy-4-methylbenzene, 2-

hydroxynaphthalene, 2-hydroxynaphthalene-4-, -5-, -6-,

'from the nitro compounds of the Formula I and having the composition HzN 503B (111) with polyfunctional acylating agents there may be used two similar or also two difierent radicals containing amino groups. If two different compounds containing amino groups are used, only one has to correspond to the Formula III.

Suitable polyfunctional acylating agents are for example phosgene, fumaric acid dichloride, terephthalic 'jacid dichloride and cyanuric chloride.

The reaction with bifunctional acylating agents is carfried out in a manner known as such. The linkage of two radicals containing amino groups in the new dyestufis via an urea group may also be carried out by reacting the urethane of one amine with another component containing amino groups. In this way compounds are obtainable in a particularly pure form which can also be produced by the reaction of two components containing amino groups with phosgene.

I The order of the reaction step required for the manufacture of the new dyestuffs may be Widely varied as has already been indicated in some cases. Insofar as metalfree azo dyestuifs are obtainedat the end of the process,

' their metallisation may be carried out in substance or as an after-treatment on the fibre; the conversion of the metal-free dyestufis or also of the intermediates formed in the course of the process into their metal complex compounds, preferably copper and'nickel complexes, is effected by known methods, for example by reaction with copper salts in an aqueous weakly acid solution.

The metal-containing dyestuffs or the dyestuif to be aftertreated with metal salts on the fibre obtainable by the process according to the invention are especially suit able for dyeing fibres of natural or regenerated cellulose. The dyeings are distinguished by good fastness properties, especially very good fastness to light and to wet processing, e.g. to washing.

The following examples are given for the purpose of illustrating the invention.

Example 1 V 304 parts by weight (0.1 mol) of l-hydroxynaphthalene-3,6-disulfonic acid are heated with 29.5 parts by weight of 1-hydroxy-2 diazo-6-nitronaphthalene 4 sulfonic acid (0.1 mol) and about 22 parts by weight of calcium oxide in 1400 parts by volume of water to 60-70 C. with stirring for about 30 minutes, a blue dyestufi solution thus being formed.

After completion of the coupling, the product is cooled to room temperature, rendered acid to Congo with hydrochloric acid, and the separation of the dyestufi of Formula IV is completed by means of common salt.

The dyestuff paste is dissolved in 2500 partsby volume of hot water, adjusted to pH 5-6 with sodium acetate and treated with a solution of 25 parts by weight of crystalline copper sulfate. The solution is heated to C. for 15 minutes. After cooling, the coppered dyestufi is separated with common salt, and isolated.

The dyestuft paste is dissolved in 1500 parts by volume of 3% sodium hydroxide solution, treated with 17.5 parts by weight of glucose and kept at 55 C., until the reductive linkage is completed. The dyestuff is isolated as usual. After drying, it is a dark powder which dissolves in water with a blue color and dyes cotton in bluish grey shades.

If in this example 1-hydroxynaphthalene-3,6-disulfonic acid is replaced by one of the following coupling components one obtains dyestuffs which dye cotton in the shades mentioned below:

Z-Hydroxynaphthalene-S,7-disulfonic acid a blue.-

2-Hydroxynaphthalene-3,G-disulionic acid blue. 2-Hydroxynaphthalene-3,7-disulfonica acid blue. 1-Hydroxynaphthalene-3,8-disulfonic acid blue. 1-Hydroxynaphthalene-4,S-disulfonic acid blue.

1-Hydroxy-8-chloro-naphthalene 3,6 disulfonic Example 2 0.1 mol of 1-hydroxy-2-diazo-6-nitronaphthalene-4-sulfonic acid is coupled with the equivalent amount of l-hydroxynaphthalene-3,6 disulfonic acid according to the instructions of Example 1. The isolated'dyestufl? paste is dissolved neutral in 700 parts .by volume of warm water, treated with a solution of 41 parts by weight of crystalline sodium sulfide in parts by volume of water and kept at about 55 C., until the reduction of the nitro group to the amino group is completed. The product is isolated with hydrochloric acid and re-dissolved. The paste thusobtained is coppered as usual and converted into theurea by introducing at 30 C. phosgene into the solution which is kept soda-alkaline. The dyestuff is 'separated'out with sodium chloride and isolatedfAfter '5 drying, it is a dark powder which dissolves in water with a bluish violet color and dyes cotton in a violet shade.

If using instead of phosgene; cyanuric chloride or fumaric acid dichloride as b flmctional acylatingagent, similar dyestuffs are obtained which dye cotton in violet shades.

Example 3 If 0.1 mol of the copper complex amino group containing azo dyestufi obtainable according to the instructions of Example 2 and having the composition O?CuO SOaH is further diazotized in an acetic acid medium in usual manner, coupled with 1-amino-2-methoxy-S-methylbenzene, diazotized again in an acetic acid medium and coupled with Z-hydroxy-naphthalene-3,6-disulfonic acid, there is obtained, after coppering with de-alkylation, the dyestufi of the formula CH N=N N= QM Ho. H 8 Cu-- BOIH which dissolves in water with a blue color and dyes cotton in bluish grey shades.

Example 4 When coupling, as described in Example 1, 0.1 mol of 1-hydroxy-2-diazo-6-nitronaphthalene-4-sulfonic acid with the equivalent amount of 1-.(4-.sulfophenyl)-3- methyl-pyrazolone-(S) and converting the monoazo dyestuft thus obtained into the copper complex compound, there is obtained, after reductive linkage by means of glucose in an alkaline medium, a dyestufl which, after drying, is a dark powder dissolving in water with a violet color and dyeing cotton in covered violet shades.

Example 5 32.8 parts by weight of the monoazo dyestufl? of the formula are coupled, similarly to the instructions of Example 1, with 29.5 parts by weight of l-hydroxyQ-diazo-fi-nitronaphthalene-Asulfonic acid and converted into the copper complex of the following composition:

. OH 31 out 7 1I=NOSO:H

SOIH

After reductive linkage, a dyestufl is obtained which, after drying, is a dark powder dissolving in water with a brown color and dyeing cotton in brown shades.

Example 6 to the instructions of Example 3, 14.4 parts by Weight of 2-hydroxynaphthalene are coupled with 6 the equivalent amount of l1hydroxye2 diazo=6rnitronaph thalene-4-sulfonic acid, and the. nitromonoazo (1355M thus obtained is reductively linked with alkaline medium. A dyestufi is obtained of the formula inan which dyes cotton in blue shades the fastness properties of which can be improved byafter-treatment with copper salts. I V

1 instead of Z-hydroxynaphthalene one of the following coupling components is used:

2-hydroxynaphthalene-6-sulfonic acid, 2-hydroxynaphthalene-6-sulfonic acid amide,

l-hydroxy- 6-b enzoylaminonaphthalene-3-sulfonic acid,

y yo yhy mx p nv m sm nathalene-3 -sulfonic acid, A

1-phenyl-3-methylpyrazolone-( 5 l-phenyl-3carboxypyrazolone-( 5 valuable dyeings are obtained on cotton, the iastn'ess properties of which can be improved by after-treatment with copper salts. i Example 7 100 parts by weight of cotton are introduced at room temperature into a dyebath containing 4000 parts by volume of water, 2 parts by weight of the dyestufi obtainable according to Example 3, 1 part by weight of sodilfir carbonate and 20 parts by weight oi sodium The dyebath is heated to C. within 30. minutes and kept at 90-95 C. for 30 minutes. The cotton is then rinsed and dried. A blue grey dyeing of very good fastness to light is thus obtained.

Example 8 OH HO OgN HO It can be converted into the copper complex compound by the method described in Example 1.

The paste of the copper complex compound is stirred with 1000 parts by volume of water, 40 parts by volume of glacial acetic acid and then diazotized with 18 parts by volume of 30 percent sodium nitrite solution at C. When the diazotization is complete and the soda alkaline solution of 30.4 parts by weight of 2-hydroxynaphthalene- 3,6-disulfonic acid in 300 parts by volume of water and 200 parts by volume of 20 percent soda solution are .added at 0 C. The dyestutr" thus obtained can be reductively linked as described in Example 1 and coppered as usual. One obtains the copper complex of the pentakis azo dyestufi corresponding to the formula H018 l OH HO N=N OsH 1f=N (I) 0 H018 OH H Hots It represents in the dry state a dark powder which dissolves in water with blue coloration and dyes cotton in blue grey shades.

Example 9 OH HO If dried the dyestufl represents a dark powder which dissolves in water with blue coloration and which dyes 'cotton in greenish grey shades.

We claim:

1 1. A dyestuff selected from the group consisting of an fo,o'-dihydroxy azo dyestufi corresponding to the formula i SOzH wherein X stands for a member selected from the group consisting of-azo and azoxy, R means a radical selected from the group consisting of the naphthalene, azo ben- 75 3 v zene, azo naphthalene and benzene azo naphthalene series, said radical being substituted by at least one member selected from the group consisting of a sulfonic acid and hydroxyl group and R stands for HO OH SO H when R; is a radical of the pyrazolone series, R means a coupling component selected from the group consisting on no sorn p N=N 7 v H018 N=N i v l on: H H 0,11 l 5 of the naphthalene, pyrazolone, azo benzene, azo naphthalene and naphthalene azo benzene series, said coupling component bearing the OH-group in o-position to the azo bridge, and the copper complex compound of said azo dyestufi. Y

2. A copper containing azo dyestufl corresponding to the formula 4 H llI=N-- HOzS N=N 501B (0) H H wherein the members R are radicals of naphthalene sulfonic acids bearing the complex-linked oxy group o-position to the azo bridge.

3. A copper containing azo dyestuif corresponding to the formula -O 0Cu-0 son;

wherein the members R and R are radicals of naphthalene sulfonic acids bearing the complex-linked oxy groups in o-position each of the azo bridges.

4. The copper containing pentakis azo dyestufi corresponding to the formula I 110 -Cu S OEH O Rois Gu 80111 5. The copper containing pentakis azo dyestufi corresponding to the formula 6. The copper containing trisazo dyestufi corresponding 7. The uisazo dyestuflf corresponding to the formula to the formula OH E0 on E0 S0111 80,11 s0=H I I l 26 N: =N

N: (3) N=N N=N N=N 8 smH smH Hoe! 80:11 30 References Cited in the file of this patent UNITED STATES PATENTS 2,919,269 Nickel et a1. Dec. 29, 1959 

1. A DYESTUFF SELECTED FROM THE GROUP CONSISTING OF AN O,O''-DIHYDROXY AZO DYESTUFF CORRESPONDING TO THE FORMULA 